turnserver no-udp-relay选项无效

最近在搞互动直播，apprtc+coturn方案

本来想禁用掉udp relay，但发现turnserver开启no-udp-relay选项后直接就relay不通了

找到google group里面的一篇帖子

https://groups.google.com/forum/#!topic/turn-server-project-rfc5766-turn-server/CVfxzfnfvqM

意思是说：

-no-udp-relay is about communications with peers (the relay side). And it is not supported in webrtc. -no-udp is about communications with clients (client side). It is supported in webrtc.